Studies on amylolytic bacteria in Cochin backwaters

This thesis Entitled Studies on amylolytic bacteria in cochin backwaters.This thesis presents a detailed account of the disribution of amylolytic bacteria in water. sediment. fishes ( Etroplus suratensis and Liza parsia) • prawns ( Penaeus indicus and Metapenaeus dobsoni) and clams ( Sunetta scripta and Meretrix casta) from Cochin backwaters. genera-wise distribution of amylolytic bacteria, ability of selected strains to grow and produce amylase at various physico-chemical conditions. Regulation of amylase synthesis anrt characters of amylases producer by these halophilic bacteria.Amylolytic bacteria are distributed widely in water. sediment. fishes. prawns and clams of Cochin back waters. 53% of the total isolates tested were capable of producing amylase. Maximum number of arnylolytic bacteria were present in Metapenaeus dobsoni. In general, the gut region of aquatic animals harboured more amylolytic bacteria than the gill or surface. These bacteria may help in the digestion of starch present in their food.Presence of ions in the medium was found to be essential for growth and amylase production. It was found that this ionic requirement is not highly specific. Sorlium chloride could be replaced by potassium chloride. or magnesium chloride to some extent I without affecting growth and amylase production. The important function of these ions may be to maintain the osmotic balance between the cells and their environment.All the isolates showed the ability to grow and produce amylase using raw-starches from cassava. plantain and potato .This property suggests their role in the rdegradation of native starches in the environment

The Major Digestive Enzymes in Etroplus suratensis and Oreochromis mossambicus: Distribution and Characteristics

The major digestive enzyme activities and digestive indices were compared between Etroplus suratensis and Oreochromis mossambicus. Pepsin - like acid proteases that acts on low pH has been identified all along the digestive tract of both the fishes. Comparatively low alpha amylase activity is shown by the E. suratensis and the enzyme is distributed almost equally throughout the intestinal segments in both the species. Very low alkaline protease activity is found in the stomach of both the fishes and in O. mossambicus, the enzyme activity diminishes extensively towards the posterior portion of the intestine whereas in E. suratensis the activity increases towards the posterior part. The present study showed that lipase is one of the prominent digestive enzymes in O. mossambicus with a remarkable specific activity throughout the digestive tract than that of E. suratensis .It has been noted that O. mossambicus has a higher values for digestive somatic index, hepato somatic index, intestinal coefficient and gut Vs standard length ratio than that of E. suratensis indicating its higher digestive and metabolic capabilities. The early maturity and fast growth of O. mossambicus can be explained by their enhanced digestive indices. The compa ratively low activities of acid protease, amylase, lipase and total alkaline protease of E. suratensis revealed poor digestive capacity than that of O. mossambicus